Oxides of the type La1.85Sr0.15Cu(1-x)V(x)O4-partial were prepared with vanadium contents, x, ranging from 0 to 0.10 in increments of 0.01. Vanadium entered into solid solution in the tetragonal K-phase structure at concentrations up to x = 0.05. Further additions of vanadium resulted in the formation of SrV5O11 and an orthorombic distortion of the K-phase structure. An increase in the irreversibility of the magnetization at 4.2 K, at a vanadium concentration of x = 0.01, was attributed to Show moreOxides of the type La1.85Sr0.15Cu(1-x)V(x)O4-partial were prepared with vanadium contents, x, ranging from 0 to 0.10 in increments of 0.01. Vanadium entered into solid solution in the tetragonal K-phase structure at concentrations up to x = 0.05. Further additions of vanadium resulted in the formation of SrV5O11 and an orthorombic distortion of the K-phase structure. An increase in the irreversibility of the magnetization at 4.2 K, at a vanadium concentration of x = 0.01, was attributed to increased flux pinning due to solid solution hardening. Reduced magnetic irreversibilities and critical temperatures were observed at higher vanadium concentrations, and attributed to a loss of strontium from the K phase due to the formation of SrV5O11. Show less